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(No Model.) ,7 -Sheet-ShqetL SLD. TUCKER. TRIPPING MOTION FOR PRINTINGMACHINES.

No. 573,425. Patent @1160. 15, 1896.

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- S. D. TUCKER. TRIPPING MOTION FOR PRINTING MAUHINBS.

No; 573,425. Patented Dec. 15,1896.

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(No Model.) 7 SheetsSheet 3.

V s. D. TUCKER. TRIPPING MOTION FOR PRINTING MACHINES.

No. 573,425. Patented Dec. 15, 18.96.

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- S. D.TUOKBR.. TRIPPING MOTION FOR PRINTING MACHINES.

No. 573,425. Patented Dec. 15, 1896.

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's. D.-TUOKER. I IRIPPING MOTION FOR PRINTING MACHINES.

No."573,.425. Patented Dec. 15, 1896.

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S. D. TUCKER.

TRIPPING MOTION FOR PRINTING MACHINES. No. 573,425.

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Modem 7 Sheets-Sheet 7. S. D. TUCKER.

TRIP PING'MOTION FOR PRINTING MAGHI NES.

No, 573,425. Patented Dec. 1-5, 1896.

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UNITED STATES I PATENT OFFICE.

STEPHEN D. TUCKER, OF NEW YORK, N. Y., ASSIGNOR TO ROBERT HOE, THEODOREH. MEAD, AND. CHARLES WV. CARPENTER, OF SAME PLACE.

TRIPPING-MOTI ON FOR PRINTING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 573,425, dated December15, 1896.

Application filed November 1'7, 1892 Serial No. 452,299. (No model.)

To all whom it may concern.-

Be it known that I, STEPHEN D. TUCKER, a citizen of the United States,residing at New York, county of New York, and State of New York, haveinvented certain new and useful Improvements in Tripping-Motions forDonble-Cylinder Flat-Bed Printing-Machines, fully described andrepresented in the following specification and the accompanyingdrawings, forming a part of the same.

This invention relates to that class of printing-machines in which tworotating impression-cylinders cooperate with a flat reciprocatingtype-bed that carries two printingforms, and more especially to such ofthese machines as are provided with a single feedtable and one deliverymechanism and have their impression cylinders furnished with means fortransferring the sheets from the primary to the secondary cylinder, sothat such sheet may be perfected while passing continuously through themachine; but this invention may also be applied to suchprinting-machines when they are provided with means for feeding sheetsto each of their impression-cylinders and with two deliveries andoperate to print two sheets with one impression each. In these machinesthe cylinders must be alternately lowered into printing position, sothat each may produce an im pression during every second revolution, andduring its alternating revolution each cylinder must be raised out ofprinting relation to the bed, so as to avoid contact with theprinting-form then passing beneath it, which is a time when the cylinderdoes not carry a sheet 10 be printed. This alternate raisin g andlowering action of the cylinders is automatically performed, and amachine equipped with means for accomplishing it will properly performso long as sheets are regularly fed to it; but in consequenceof thepossibility of failing to feed the sheets regularly or other defectiveaction it is requisite that this raisingand lowering mechanism shall bewithin the control of the feeder and a tripping of the said mechanism bepossible at such times as will prevent any improper action of themachine.

The present invention provides a tripping mechanism of such improvedconstruction the gear side of the machine. plan view of the parts shownin Fig. 9, taken that it may not only operate to control the verticalmovements of the cylinders indepen dently of their automatic action, butbe capable of operating only at such times as the cylinders may properlybe so acted upon and then first upon the primary impression-cylinder andthereafter upon the secondaryimpression-cyhnder; and the inventionconsists a double-cylinder flat-bed printing-machine as is requisite toillustrate the present invention. In this view such of the lower partsas would obscure others more important to be illustrated are broken awayupon the sectionline 0 d of Fig. 2, and some of the gearing is shown indotted lines only. Fig. 2 is a trans verse sectional elevation of thesame machine on the line a b of Fig. 1, as seen in looking toward theimpression-cylinders. Fig. 3 is an enlarged sectional plan view. Figs.4, 5,

6, '7, 8, and 9 are enlarged side elevations of the cylinderraising andlowering mechanisms and of the tripping mechanism, as seen from Fig. 10is a on the sectional line of said Fig. 9; and Fig. 11 is a sideelevation of the same parts. Figs. 12 to-19 arediagrams illustrating theparts shown in various positions which they have during a completereciprocation of the typebed.

The printing-machine illustrated is, in its general characteristics, ofthe common type of machine. It consists of two rotatingimpression-cylinders A B and a flat reciprocating type-bed T, whichcooperates therewith in producin g'theimpressions necessary to perfoot asheet.

The primary impression-cylinder A and the secondary impression-cylinderB are each mounted in the f 'amework so as to be capable of verticalmovement, which is attained by mounting their shafts in journal-boxesconstructed to slide between guides, which are provided in the sideframes. These cylinders A and B are respectively provided withsheet-carrying grippers or fingers 20 21, of ordinary construction,which are rocked to close and seize the sheet in order to hold and carryit upon the surface of the cylinder and rocked to open and release thesheet when it is to be delivered by the primary to the secondarycylinder or by the secondary cylinder to the delivery devices, whichcarry it out of the machine.

The cylinders A B are so positioned as to be nearly in contact, and theyare rotated in unison by means of wheels 50 60, which do not geartogether, but respectively mesh with intermediates 52 58, which aregeared together and the former of which gears with and imparts motion tothe double-faced pinion 54 011 the outer end of the oscillating shaft12, at the opposite or inner end of which shaft is carried thebed-driving pinion 1 1.

The type-bed T horizontally reciprocates upon rollers carried by slidersS in ways V, as is usual, and it is provided centrally with a hanger, as61, which supports a doublefaced rack R, with which said pinion 14:engages. At each end of this rack R it is provided with curved shoes L,forming guideways which when engaged by the elongated inner end of theshaft 12 directs said shaft upward at one end and downward at the otherend of each stroke of the bed, and thus carries the pinion 11 from thelower to the upper and from the upper to the lower side of thedouble-faced rack R, so that it will drive the rack, and hence the bed,first in one direction and then in the other, the size of the pinion 11in this instance being such that it makes four revolutions to onecomplete reciprocation of the typebed. This shaft 12 is hung at itsouter end in a journal-box that is provided with oppositely-projectingstuds 22 23, which turn in bearings 74 75, secured to the side frame. Itis thus capable of vertical oscillation in the guide G, in whichmovement the doublefaced pinion 54 it carries first engages its one faceand then its other face with the wheel 52. The main drivingshaft- (52,which will be provided with the usual driving pulleys, is mounted in oneside frame and carries outside the frame a driving-pinion 55, (ofsixteen teeth,) which meshes with the toothed wheel 52, (anintermediate,) that gears with the cylinder-wheel 50, (of sixty-fourteeth,)

said wheel 52 in turn gearing with the wheel 53 (an intermediate) andthe latter with the cylinder-wheel ($0, (of sixty-four teeth.) ()11 itsinner end said driving-shaft carries a driving-pinion 56, (of twentyteeth,)-which gears with a wheel 57, (of fifty teeth,) that is mountedon a stud and carries a pinion 58, (of twenty teeth,) which engages awheel 59,

(of sixty-four teeth,) that is fast upon and drives the cam-shaft 18.The main shaft 62 thus drives both the cylinders and the bed, and therelation of the gearing is such that the bed-driving shaft 12 makes fourrevolutions to one of the cam-shaft 13. Of course any other gearingmight be adopted for movin g these various parts concertedly.

The type-bed T is provided with the two forms necessary to print theopposite sides of a sheet, which forms are inked by suitable inkingdevices I J, provided at the outer sides of the impression-cylinders andarranged in position to suitably ink the forms 011 the bed as they passbeneath them. A feed-board C is provided, from which the sheets may besuccessively fed to the grippers 20 of the primary cylinder A, and adelivery mechanism, as the guiding-conductors 81 and endlesscarrying-tapes S0, for receiving the perfected sheets from the grippers21 of the secondary cylinder and delivering them in succession from themachine.

It will now be understood that a sheet fed from the table 0 against thedrop-guides 83 to be taken by the grippers 20 of the primaryimpression-cylinder A, as in Figs. 12, 13, and 14, will, when carried bysaid cylinder into contact with the appropriate form on the typebed T,be printed upon one side, as in Figs. 15 and 16, while the bed istraveling in the direction indicated by the dotted arrow in Fig. 1, andthen be delivered to the grippers 21 of the secondaryimpression-cylinder B, as in Fig. 17, and be printed upon the oppositeside by that cylinder from the appropriate form on the type-bed, as inFigs. 15, 19, and 12, while the latter is traveling in the directionindicated by the full-lined arrow, as in Fig. 1, and that when thegrippers 21, carrying this perfected sheet, arrive at a convenient pointbeneath the feed-board C said grippers will be opened to release thissheet to the delivery mechanism, as in Figs. 13, 14, and 15.

In Fig. 12 the mechanisms are in the positions which they have when thegrippers of the primary cylinder are closely approaching thesheet-seizing point and just previous to the time when they close totake a sheet from the feed-board C, which is also the time when thesecondary cylinder is about to discharge a perfected sheet to thedelivery mechanism, Fig. 13 showing an intermediate position and Fig. 14the position of the parts at the moment when the grippers are closedupon the sheet.

The two forms 011 the type-bed are imposed in opposite directions, andduring the making of the first impression or printing upon one side ofthe sheet the cylinders A and B each makes one revolution and thetype-bed makes a movement in the direction of the dotted arrow, Fig. 1,the sheet being carried by the primary cylinder A and pressed intocontact with the right-hand form carried by the typebed, as in Figs. 15and 16, during which printin g operation the cylinder B, being raised,re

secondary cylinder B, as in Fig. 17.

' point the grippers open to release the onceprinted sheet and thegrippers 21 close to seize this sheet and carry it around upon theDuring the next revolution of the said cylinders A and B, at whichtimethe type-bed makes its movement in the direction of the full-linedarrow, the cylinderB, then lowered into print ing position, presses theunprinted face .of the once-printed sheet into contact with theleft-hand form carried by the type-bed, as in Figs. 18, 19, and 12, andthe cylinder A, then raised, revolves out of printing position, the twocylinders thus being actively engaged in printing only during alternaterevolutions of them. Now in order that when the primaryimpression-cylinder A is cooperating with the type-bed T to impart thefirst impression to the sheet the form carried by the bed then passingbeneath the secondary cylinder B may not have contact with thatcylinder, and that when the second impression-cylinder B is 00-operating with the type-bed T to impart the second impression to saidsheet the form car-.

ried by the bed then passing beneath the primary cylinder A may not havecontact with that cylinder, both of said cylinders are provided, as iscustomary, with automatic means for alternately raising and loweringthem at appropriate times. This raising and lowering of these cylindersis accomplished as follows: Each cylinder has its sliding journalboxesseated upon springs, as 63 64, which springs are housed in recesses inthe side frames and retained in position by means of spindles, as 85 86,which are screw-threaded and provided with nuts to adjust the resilientpower of said springs. The journalboxes at the opposite ends of thecylinder A are each provided with a pair of vertical rods 66, and thejournal-boxes at the opposite ends of the cylinder B are each providedwith a pair of vertical rods 67 68, which rods extend through saidjournal-boxes, are guided in suitable slots in the side frames, and havetheir lower ends secured to vertically-sliding heads 69 7 0, that movein suitable guideways provided in the side frames, and all of these rodshave screw-threaded lower ends furnished with nuts,whereby the pressureof the cylinders upon the forms may be accurately adjusted.

The cylinders are drawn downward. into printing position by the actionof toggles, as 3 4: and 5 6, when said toggles are straightened and areraised by the action of the springs 63 64 when said toggles are rockedout of alinement. The members 3 5 of the toggles are pivoted to the sideframes, and the members 4 6 of the toggles project from rock-shafts 1718, whose bearings rock in the sliding heads 69 70, that are duplicatedin the opposite side frames of the machine, and from which rock-shaftsatone side of the ma chine depend rock'arms 15 16, through which saidrock-shafts are actuated by means of connecting-rods 24: 25, which havehooked ends, so that they may be engaged with and disengaged from studsat the ends of said rock-arms 15 16. Each of these connecting rods 24 25is a prolongation of a yoke, as 28 29, both of which yokes embrace andare guided by the cam-shaft 13, and these yokes are each provided withpairs of friction-rolh ers, as 7 9 and 1 2, which are respectivelyengaged by the impression-cams 26 27,which cams, being fast on saidshaft 13 and of like shape and alinement, cause the connectingrods 24 25to concertedly reciprocate.

Normally the connecting-rods 24 25 have their hooked ends engaged withthe studs on the rock-arms 15 16, as in Fig. 4, and it there foreresults that as the cam-shaft 13 revolves the toggles 3 1 and 5 6 arealternately rocked out of alinement to permit a cylinder to rise out ofprinting position (see cylinder A in Fig. 1) and into alinement to drawa cylinder downward into printing position. (See cylinder B in Figs. 1and 12.) The camshaft 13 makes one revolution to two revolutions of thecylinders A B and to each complete reciprocation of the type-bed, andthe impression-cams 26 27 are so positioned on the camshaft 13 that thecam 26 begins to straighten the toggles 3 4 to depress theimpression-cylinder A where the grippers 20 of that cylinder are seizingthe sheet, as in Fig. 14, so as to carry it onward to be printed, whilethe cam 27 begins to operate to straighten the toggles 5 6 to depressthe impression-cylinder B as the grippers 21 of that cylinder are movingaway from the sheet-delivery point and are carrying the sheet onward fora sec- 011d printing, as in Fig. 17, the lowering of each cylinder thusbegun being completed to bring it into printing relation thereto justbefore it is engaged with its cooperative form on the bed. The movementsare also so timed that when the primary cylinder A is pressing a sheetinto contact with one form upon the type-bed and printing the firstimpression thereon the toggles 3 4: will be straightened, so as todepress the said cylinder into printing position, and at the same timethe toggles 5 6 will be thrown out of alinement, so as to permit thecylinder B to be raised out of printing position, (see Fig.

15), and when this sheet is carried uponthe;

secondary impression-cylinder B and is. be-

ing pressed by it into contact with the other out of alinement, so as topermit the primary.

cylinder to be raised out of printing position with respect to the otherform and thus prevent its contact therewith.

The latter positions of the toggles are shown in Fig. 1, where the partsare in the positions (See Fig. 18.)

they have at the time when the primary impression-cylinder is about toreceive a sheet and the secondary impression-cylinder is just finishingits impression and the type-bed is traveling in the direction of thefull-line arrow. So long as sheets are regularly fed from the table 0 tothe grippers 20 of the primary cylinderA these printing operations mayproceed without interruption and a sheet will be perfected at eachsecond revolution of the said cylinders A and B; but it sometimeshappens in these rapidly operating mechanisms that a feeder will fail tofeed a sheet to or properly adjust one, so that it will be taken intothe machine by the grippers 20 of the primary impression-cylinder A, andsince, in case of the absence of a sheet on said cylinder, it willresult that the form on the type-bed will, if the primaryimpression-cylinder is brought into printing position, imprint animpression upon the naked blanket carried by said cylinder, mechanismmust be provided whereby said cylindershall be maintained out ofprinting relation to its form during any revolution of it when itcarries no sheet, and since, if the primary cylinder A has made itsactive or printing revolution without being supplied with a sheet, therewill be a like absence of a sheet upon the secondary impression-cylinderB during its succeeding printing revolution, when it ordinarily would belowered into printing position, said cylinder B must also be maintainedout of printing relation to the bed during its said succeedingrevolution. This maintaining of the two impression-cylinders out ofprinting position at such times as they are unprovided with a sheet tobe printed upon is accomplished by a tripping mechanism whereby thetoggleconnecting rods 24 25 are tripped, so that during the appropriaterevolution of each of these cylinders their toggles may not bestraightened to draw the cylinder down into printing position.

In practical operation if the grippers of the cylinder A fail to take asheet during the printing rotation of that cylinder the toggles of thatcylinder, as has been shown, must be tripped, so that it will remain outof printing position, and since the secondary cylinder, which at thistime, when irregular action has required the tripping movement to bemade, will be operating to complete the printing upon or perfecting aprevious sheet already received by it from the primary cylinder, (seeFigs. 19, 12, and 13,) it becomes necessary that the trip-motion shallbe so arranged to operate that the primary cylinder A will be the firstto trip, and that its tripping shall always be followed by the trippingof the secondary cylinder after it has printed the sheet then upon itand been raised out of printing position, thus insuring the perfectingof the sheet then being acted upon by the secondary cylinder and leavingboth cylinders raised for appropriate non-action in the absence of asheet. It is also necessary, in order to secure a perfeet operation ofthe cylinders as well as a perfect cooperation between them, that itshall only be possible to trip the primary eylinder at an appropriatetime, which is when the cylinder is raised out of printing position andat a time when it should receive a sheet, and that the primaryimpression-cylinder A shall always come into printing position first, sothat the secondary cylinder when it operates shall always be furnishedwith a sheet. To accomplish these results, the constantlyrevolvingcam-shaft 13, which carries the impression-cams 26 27, through which thetoggles are automatically operated to raise and lower first oneimpression-cylinder and then the other, and which makes one revolutionfor each sheet fed or during a complete reciprocation of the type-bed,is provided with a tripping-cam 30, that is capable of moving sidewiseupon said shaft, guided by a feather 8, which movement is accomplishedby means of a tripping-rod 37. This tripping-rod 37 is seated upon aspring 38 and moves a treadle or rock lever 39, fast upon an oscillatingshaft 40, that carries rock-arms 41 42, which enter a groovedcollarattached to the cam 30, this cam being thus moved-inward by therockarms 41 42 and outward by the spring 38. When moved inward, this cam30 as it revolves bears upon the inner ends of and depresses rock-arms31 32, which project from hubs that rock freely upon shafts 10 11 andhave offsets that abut against similar offsets on hubs fast 011 saidshafts, from which extend rock-arms '34, the said arms 33 34 being madeseparate pieces, so as to provide for the hand tripping hereinafterexplained. The movement of the rock-arms 31 32 is thus transmitted tothe rock-arms 33 34, which thus act to lift the hooked ends of theconnectingrods 24 25 free from the studs on the ends of the togglerock-arms 15 16, and these operations are so timed that this cam 30 willdisconnect said rods 24 25 just before the impression-cams 26 27respectively begin the operation of throwing the toggles into alinement,whereby one or the other cylinder would be lowered into printingposition. When this tripping-cam 30 is free to do so, it is movedoutward by the spring 38 and becomes inactive, and it then revolves withthe cam- I shaft, but at one side of and therefore inoperatively withrelation to the arms 31 To perform the tripping operation, thetripping-rod 37 is depressed, thus through the treadle-lever 30, therock-shaft 40, and its rock-arms 41 42 throwing the tripping-cam 3Olaterally into the vertical plane of or in alinement with the studs orbowls on the inner ends of the arms 31 32, as in Fig. 4, and as this camconstantly revolves in the direction indicated by the arrow its highpart will bear upon the inner end of the rock-arm 31, raise the rock-arm33, lift the connecting-rod 24., and disengage its hooked end from therockarm 15, as in Fig. 6. This causes the rod 24, when moved by the cam26, to pass ineffectively over the rock-arm 15, thus leaving the primarycylinder in its raised or non-printin g position, during which movementof the rod 24 its companion rod 25 will have drawn the rock-arm l6inwardly, thus throwing the toggles 5 6 out of alinement and allowingthe secondary impression-cylinder to be raised, which movement is shownin Fig. 6. \Vhen, however, the high part of the tripping-cam 30 duringthis same rotation of it reaches and bears upon the inner end of therock-arm 32, which is before the connecting-rod 25 begins its returnmovement, said rock-arm 32 will be actuated to raise the rock-arm 3a tolift the hookedend of the rod 25 out of engagement with the rock-arm 16,and thus disconnect these parts, as in Fig. '7, so that during itsreturn or outward movement this rod 25 will pass ineffectively over thearm 16. Thus when tripped the primary impression-cylinder A will remainraised out of printing position and the secondary impression-cylinder Bwill also remain raised, and the two cylinders will be maintained insuch raised positions so long as the tripping-rod 37 and treadle-lever39 are depressed.

In order that the tripping-cam 30 may be moved laterally inward to carryits enlarged part intooperative relation to the rock-arms 31 32, saidarms are so positioned that normally their inner ends are a littlefarther away from the cam-shaft 13 than is the low part of the cam, andas said cam, when inoperative, turns in a different vertical plane andwhen operative turns in the same vertical plane in which said armsvibrate and slides laterally outward from one position to the other itfollows that it can only be moved over the ends of and into operativerelation to said rock-arms when, during its rotation, its low part islaterally opposite said arms, as in Figs. 1, 4, 19, 12, and 13, and therelative extent of the enlarged and low parts of said cam is such andthe enlarged part of the cam is so related to the said rock-arms intheirnormalpositions that the cam can only be moved past said rock-armsfor engagement therewith after the rear end of its enlarged part hascleared the position of the rock-arm 32 (as is about to be accomplishedin Fig. 8) and before the leading end of its enlarged part arrives atthe position of the rock-arm 31, (as is about to be accomplished in Fig.4,) and thus it must always first engage the rockarm 31 that moves thetripping devices of the primary cylinder, and then in proper time engagethe rock-arm 32 that moves the tripping devices of the secondarycylinder. This tripping-cam makes one revolution to two revolutions ofthe impression-cylinders, and as the arms 31 32 are normally so relatedto it that while about a quarter-revolution of the cam will take placebetween the contact of its enlarged part with the rock-arm 31 and itssubsequent engagement with the rock-arm 32, and consequently between thetripping of the primary and secondary cylinders, said tripping-cam 30can only be moved into action during about a sixth of a revolution ofit, for the reason that when the rear end of its enlarged part hascleared the plane occupied by the arm 32 the head or leading end of itsenlarged part will have arrived in such a relation to the arm 31 thatafarther sixth-revolution of it will bring said leading end at the planeoccupied by the rock-arm 31. The movement of the cam 30 to produce thetripping action can therefore can only be made after its enlarged parthas passed the end of the rock-arm 32,which acts upon the trippingdevices of the secondary cylinder and before the leading end of itsenlarged part has reached the inner end of the rock-arm 31, which actsupon the tripping devices of the primary cylinder, and then only whilesaid cam is making about a sixth of a revolution, during which theimpression-cylinders will make about a one-third revolution. \Vhen,however, the leading portion of the enlarged part of this cam passes theinner end of the rock-arm 31 without that cam having been moved sidewiseinto en gagement with said rock-arm, it will of course be too late toslide the cam, since it will then abut laterally against said rock-arm,and thus be prevented from moving past it, and hence there canbe notripping action through either rock-arm until the enlarged part of thecam has passed the innerends of both of the rockarms 31 32 and againpresents its low part to them, as in Figs. 1 and 19.

Whemas in case of failure to provide it with a sheet, it becomesnecessary to trip the cylinder A so as to maintain it out of printingposition, its companion cylinder B will also be held in a raisedposition at the proper sequential time. This tripping action may beaccomplished, as has been shown, during about a third of a revolution ofthe impression-cylinders or while the low part of the tripping-cam 30 ispresented to the rock-arms 31 32, but its position relative to theimpression-cams 26 27 is such that the cam 26 will act upon the rod 24very shortly after the leading end of the cam 30 reaches a point where,if it has been moved into the same vertical plane, it will previouslyact upon the rockarm 31 and uncouple the rod 24. The concerted movementof these cams 30, 26, and 27 is so timed with relation to the rotationof the cylinders that the low part of the cam 30 is only in position toenable it to be moved sidewise over the rock-arms 31 32 during thatthird revolution of the cylinder A when the grippers 20 are approachingand passing be yond the sheetfeeding point,where said grippers close totake a sheet from the feed-board O, which movement is substantiallyshown by Figs. 19, 12, 13, and 14, and the mechanisms are also so timedthat the extent of travel of said grippers beyond the feeding-point,during which the tripping may be effected, shall not be too great, forthe reason that the tripping must be effected before the impressioncam26 begins tomove the rod 24 to straighten when once set in to operation,shall effectively the toggles 3 4 to depress the cylinder A intoprint-in g position, which depression of it when no tripping is requiredshould be begun im mediately after the grippers have taken a sheet atsaid feeding-point, because such depression is slowly made while thecylinder turns considerably and must be completed just before the headof the sheet meets the form which is to print upon it, as in Fig. 15.

From the foregoing it will be seen that the primary cylinder will alwaysbe tripped first and that when it has been tripped the secondarycylinder must also be tripped during its next alternating revolution.This is requisite beeause the tripping of the primary cylinder occurswhen that cylinder has not taken a sheet during their coincidingrevolutions when the secondary cylinder is carrying and perfecting asheet, as in Figs. 18, 19, 12, and 13, while duringits succeedingrevolution this secondary cylinder will be without a sheet, not havingreceived one from the primary cylinder. It Will also appear that afterthese cylinders have been successively tripped the primary cylinder willalways be the first to return to printing position through thewithdrawal of the cam 30, followed by the secondary cylinder, and thisis requisite because it is the primary cylinder to which is fed thesheet to be printed; first on one side by the primary and then on theother side by the secondary cylinder, and if the secondary cylinder wasthe first to be brought into printing position it could not then havereceived a sheet from the primary cylinder, and hence it is that the cammust be locked against withdrawal until the primary cylinder oncetripped is again carried into position to take a sheet.

It is essential that the tripping mechanism,

operate to retain the primary cylinder raised out of printing positionand continue to so operate until the entire motion is completed withrespect to both cylinders.

The tripping rock-arm 31 actuates an auxiliary rock-arm 35, and thetripping rock-arm 32 actuates a similar auxiliary rock-arm 36, and theserock-arms 35 36 respectively engage collars provided on rods 46, thatrespectively depend from rock-arms 43 44, projecting from the oppositeends of the rockshaft 40. Thus, when the treadle-lever 39 is moved andthe cam 30 is entered into even slight engagement with the rock-arm 31and said arm is rocked to lift the rod 24, the auxiliary rock-arnr 35 atonce engages and lifts the rod 45, and thus forces through theintermediate devices the tripping-cam 30 all the way inward, and thussupplements to completion any partial movement of thecam caused by afaulty foot movement of the op erator and when the high part of the cam30 engages the rock-arm 32 the auxiliary rockarm 36 is lifted to pressagainst the collar on the rod 46 with like effect. These arms 35 36 thussuccessively continue to bear upwardly upon the rods 45 46 and pressinwardly the arms 41 42 until the high part of the cam has passed therock-arm 32, thereby preventing the withdrawal of the tripping-cam 30from engagement with its operating rock-arm 31 or 32 so long as one ofthe rods 24 or 25 is held by its rock-arm 31 or 32 disconnected from therock-arm 15 or 16 of the toggles. By these arrangements a timely as wellas a complete tripping of both cylinders in their appropriate order issecured, and the tripping cam once set into operation is moved into andlocked in position during its entire period of active operation.

In making the tripping action the foot-le ver 37 is quickly depressed toset the parts into action, which action, as has been explained, will,when once begun, be carried out in proper time with respect to bothcylinders. If after such tripping action a sheet is properly fed to andtaken by the grippers of the primary cylinder A when next in posi tionto receive a sheet and the foot-lever 37 having in the meantime beenreleased, the cam 30 will, after it has been compelled to complete itsaction, be moved by the spring 38 into its inactive position, theconnectingrods 24 25 will engage the rock-arms 15 16, and the printingoperation will regularly proceed, the cylinders A and B beingautomatically raised and lowered until the necessity arises for anothertripping action, which will be accomplished as has been explained.

In inking up the forms and when repeated failures to properly feed asheet occur this tripping mechanism may be continued in action for anynecessary period.

It is further important that a means shall be provided for raisingeither impression-cylinder by hand-tripping, so as to remove thecylinders from their printing positions while making the forms ready forprinting. This is accomplished by elongating the shafts 1O 11, to whichthe rock-arms 31 32 are secured, so that they protrude beyond or extendconveniently near to the side frame and providing them with hand-leversII P, which, upon being appropriately moved, will rock said shafts-totrip and uncouple the rod 24 or 25, thus permitting the toggles to berocked out of alinement and a cylinder to be raised by the action of thespring 63 or 64; but it is necessary that this hand-tripping shall notoccur during the printing period of either cylinder. To govern thishand-tripping a safety-guard N is mounted fast upon the cam shaft 13, soas to make turn for turn with the impression-cams 26 27 and tripping-cam30, and it has a rim that is normally opposed to lozenge-shaped studs 0e, projecting from the sides of the levers II P, which rim is providedwith an opening or omitted part so proportioned and related to the cams26 27 30 as to provide for the passage of the studs 0 c and hence forthe hand movement of the levers II P only during the non-printingmovement of the cylinders, at which time the impression-cams 26 27operate the toggles for the regular printing operation and the cam 30may trip the toggles.

It will be observed that if the impressioncams 26 27 are alone activethe rock-arms 31 32 are not moved, and hence their shafts are notrocked, but when the cam 30 is brought into action by the foot-trippingthese arms 31 32, acting through the rock-arms 33 34, rock their shafts10 11 and throw the levers II P inward, the studs 0 and e of whichlevers are then in oved through the opening in said guard and thereaftertravel against its inner periphery, as in Fig. 7, until, the cam 30being free to move sidewise, the normal position of the levers isattained. So, also, when handmoved the studs of these levers H P willsimilarly travel within the guard and be appropriately released andrestored to their normal positions.

That I claim is 1. The combination with mechanisms for raising andlowering the impression-cylinders, of rock-arms operating to trip saidmechanisms out of action, a revolving trippingcam having its enlargedpart of such relative extent that it can be moved laterally intooperative position over said arms but once during each revolution of it,and, means for sliding said cam, substantially as described.

2. The combination with mechanisms for raising and lowering theimpression-cylinders, of rock-arms for tripping said mechanisms out ofaction and a sliding tripping-cam for actuating the arms, the rock-armsbeing mounted in such positions with relation thereto that said cam canonly be moved into engagement with said arms when the low part of thecam is opposite the ends of both of said arms, substantially asdescribed.

3. The combination with mechanisms for raising and lowering theimpression-cylinders, of tripping rock-arms for disconnecting saidmechanisms and a sliding tripping-cam for actuating the rock-arms, theinner ends of which rock-arms are so related to the cam and the latteris so constructed that during its fop ward rotation it can only be movedinto engagement with the rock-arms after its high part has passed thetrip-arm for the secondary cylinder, thus compelling the tripping actionto be first performed with respect to the primary cylinder,substantially as described.

p 4. The combination with mechanisms for raising and lowering theimpression-cylinders, of tripping rock-arms for disconnecting saidmechanisms and a sliding tripping-cam for actuating said rock-arn1s,which rock-arms are mounted with their inner ends at one side of thecam-shaft so related to each other and to said cam that during itsforward rotation it shall first operate the tripping rock-arm of theprimary cylinder and then operate the -tripping rock-arm of thesecondary cylinder,

substantially as described.

5. The combination with mechanism for raising and lowering animpression-cylinder, of a tripping rock-arm operating to discon nectsaid mechanism, a tripping-cam for actuating said arm, means for slidingsaid cam laterally into engagement with the tripping rock-arm and anauxiliary rock-arm moved by the tripping rock-arm to press said cam intoand hold it in complete engagement with the tripping rock-arm,substantially as described.

6. The combination with mechanisms for raising and lowering theimpression-cylinders, tripping rock-arms operating to disconnect saidmechanisms, a tripping-cam for actuating said arms, means for slidingsaid cam laterally into engagement with the tripping rock-arms, andauxiliary rock-arms respectively moved by the tripping rock-arms topress said cam into and hold it in complete engagement with the trippingrock-arms, substantially as described.

7. The combination with mechanisms for raising and lowering theimpression-cylinders and rock-arms operating. to trip said mechanismsout of action, of hand-levers independently operative to move said arms,and a rotating guard engaging said levers to control their movements,substantially as described.

8. The combination with mechanism for raising and lowering theimpression-cylinders, the tripping rock-arms for disconnecting saidmechanisms and the sliding trippingcam, of the rocking shaft 40, itsarms 41, 42, 43, 44, rock-arms 35, 36 and means connect ing the arms 35,36 and 43, 44, substantially as described.

9. The combination with the toggle rockarms 15, 16 impression-cams, 26,27 and connecting-rods 24, 25 of the sliding cam 30, rockarms 31, 33 and32, 34, substantially as de scribed.

10. The combination with the toggle rockarms 15, 16, impression-cams 26,2'7, and connecting-rods 24, 25, the sliding cam 30, rockarms 31, 33 and32, 34, of the rocking shaft 40, its arms 41, 42, 43, 44, rock-arms 35,36 and rods 45, 46, substantially as described.

11. The combination with mechanisms for raising and lowering theimpression-cylinders, roclcarms operating to trip said mechanisms out ofaction, a revolving trippingcam coacting with said rock-arms, and arockshaft carrying means for sliding said cam into operative position,of intermediate devices connecting said rock-arms and rockshaft and.operating to compel the tripping operation to be completed when oncebegun, substantially as described.

12. The combination with mechanisms for raising and lowering animpression-cylinder, a rock-arm operating to trip said mechanisms out ofaction, a revolving tripping-cam coacting with said rock-min, and a.rock-shaft In testimony whereof I have hereunto set carrying means forsliding said cam into opmy hand in the presence of two subscribingerative position, of intermediate devices eon- Witnesses.

necting said rock-arm and rock-shaft and 0p- STEPHEN D. TUCKER. 5crating to compel a tripping operation to be Vitnesses:

completed when once begun, snbstantiallyas F. V. II. CRANE,

described. E. L. SPEIR.

